rdv live from Tokyo

See also Wook's blog for the other half of the Quantum computing/computer graphics blogalog.

Thursday, August 31, 2006

World Go Oza

The Toyota & Denso World Go Oza, a single-elimination tourney featuring 32 of the world's top players, is taking place right now in Tokyo. Japan started with ten players, but only three made it to the second round. The two North American representatives, three European representatives, and one Central/South American representative were all eliminated in the first round. The eight quart-finalists were 3-3-2, Korean, Chinese, Japanese. The Asia-at-large player (from Hong Kong) and Taiwanese player were both eliminated in the second round. Three of the four remaining players are (South) Korean, with one Japanese player. The semifinals are tomorrow, ending a week of intense play, but the finals won't be played until January 6-8.

Lee Chang Ho is one of the remaining four; many people seem to consider him the top player in the world.

My confusion is compounded by being unable to read the Chinese characters for many of the non-Japanese names (including the remaining nominally Japanese player, Chang Hsu, who is probably Chinese-born, if I guess right), and the fact that the Japanese assign a different phonetic reading to all of those names than their native readings, which makes it hard to match up the romanized version of their home-country names with the Japanese pronunciation.

Tuesday, August 29, 2006

Rose on Analog

Gordie Rose, of D-Wave Systems, has a new blog, and in a recent post talks about hating the gate model, and his strong preference for adiabatic quantum computation. Interestingly, he refers to the gate model as a useful theoretical construct but impractical to implement, whereas cluster state and adiabatic are practical.

My opinion, admittedly less informed than Rose's, is exactly the opposite. This comes, no doubt, from my background as a classical digital computer guy. I know how to create languages and compilers for them, and how to program them, how to build them, how to make them fault tolerant. Despite having taken a class from Carver Mead, I understand almost none of those critical topics for analog (whether quantum or classical).

Moreover, many quantum algorithms are essentially digital in nature (though the interference in the QFT can be described as an analog phenomenon). The best use of cluster-state computing we know of at the moment is as a substrate for the circuit model. And, at least for, say, digital arithmetic (something I know well), the cluster-state model uses one hundred times the resources of a more straightforward implementation. Michael Nielsen is working on some intriguing things, combining cluster-state with error correction in ways that may be more robust or more efficient, but that 100x penalty is a big one to overcome as we struggle to get even a few gates working properly.

Don't get me wrong -- I'm a big fan of analog computing. But Rose's opinion I find a little startling, and it will prod me into some more reading on adiabatic quantum computation, which has been on my list of things to do anyway...